Should the Mercedes-Benz C260L use 95 or 98 octane gasoline?

[OliviaRose]

Mercedes-Benz C260L can use 95 octane gasoline. This octane rating is recommended in the vehicle's official user manual. In addition to checking the appropriate gasoline grade in the user manual, the recommended octane rating can also be found on the fuel tank cap of the Mercedes-Benz C260L. Typically, the required gasoline grade can also be determined based on the engine's compression ratio. Vehicles with a compression ratio between 8.6-9.9 should use 92 octane gasoline, those between 10.0-11.5 should use 95 octane, and higher compression ratios may require 98 octane. However, with the application of new technologies, the compression ratio alone cannot solely determine the appropriate gasoline grade. High compression ratio engines can also be tuned to use lower octane fuel, as factors such as ignition timing, turbocharging technology, and Atkinson cycle technology also play a role. Generally, higher octane gasoline has a higher octane rating and better anti-knock properties. 92 octane gasoline contains 92% isooctane and 8% n-heptane, while 95 octane gasoline contains 95% isooctane and 5% n-heptane. If the Mercedes-Benz C260L occasionally uses the wrong gasoline grade, simply switch back to the correct grade after consumption. However, prolonged use of the wrong octane rating can have the following effects: Using a higher octane gasoline in a vehicle designed for lower octane will not cause damage, but the increased octane rating may alter the fuel's ignition point, leading to delayed combustion. This reduces the engine's power output and thermal efficiency, resulting in poorer performance. Using a lower octane gasoline in a vehicle designed for higher octane can cause engine knocking. The significantly lower octane rating lowers the fuel's ignition point, causing premature ignition during the compression stroke. If combustion occurs before the spark plug fires, resistance is created during the upward stroke. This resistance makes the engine run very unstably. Mild knocking may only increase noise without significant engine damage, but severe knocking indicates serious engine conditions, affecting not only driving stability but also causing abnormal wear on pistons and cylinders, potentially leading to cylinder scoring.